They have chloroplasts, that combine carbon dioxide and water, with light energy from the sun, to create oxygen and sugar, a form of chemical energy.

植物细胞有叶绿体，可以结合二氧化碳和水，只要有来自太阳的能量，就可以制造氧和糖，这属于化能量。

Today, every single plant has cells like this, full of chloroplasts and mitochondria.

今天，每一株植物都有这样的细胞，充叶绿体和线粒体。

Plant cells also contain chloroplasts which are filled with a chemical called chlorophyll.

植物细胞还包含叶绿体，里面充了一种叫做叶绿素的化物质。

Their veins shuttle nutrients in and out of the leaf, and the cells in between are packed full of chloroplasts, the cellular machines responsible for photosynthesis.

它们的叶脉将营养物质进出叶片，叶脉之间的细胞充了叶绿体，叶绿体是负责光合作用的细胞机器。

Over time, that evolved into a chloroplast, the organelle that does photosynthesis.

随着时间的推移，它们进化成叶绿体，也就是进行光合作用的细胞器。

What makes Elysia and a few closely related species in the Mediterranean and Pacific unique is how long they can hold onto chloroplasts — most other slugs keep them for a few weeks at most.

让绿叶海天牛及少数相近种群，成为地中海和太平洋中独一无二的存在，它们能够将叶绿体保存的足够久——其他大部分的鼻涕虫最多能保存几周。

Finally, let's look at the chloroplast.

最后是叶绿体。

Chloroplasts are found only in plant cells and contain chlorophyll.

叶绿体仅存在于植物细胞内，而且含有叶绿素。

And we know that this happened for a bunch of different reasons, from similarities in chloroplasts' and bacteria's DNA, to chloroplasts' two membranes, which support the theory that they were once engulfed by a larger cell.

我们知道发生这种情况有很多不同的原因，从叶绿体和细菌 DNA 的相似性，到叶绿体的两层膜，这支持了它们曾经被一个更大的细胞吞没的理论。

This makes the chloroplasts able to sustain themselves for longer inside the slug.

这使得叶绿体能够在鼻涕虫体内维持更长时间。

Simple plant cells may have only one or two chloroplasts in them.

简单的植物细胞可能仅有一个或两个叶绿体。

For one thing, plant cells contain chloroplasts, which are organelles that convert carbon dioxide gas from the air into sugars using energy from the Sun — AKA, photosynthesis.

首先，植物细胞含有叶绿体，叶绿体是利用来自太阳的能量将空气中的二氧化碳气体转化为糖的细胞器，也就是光合作用。

Some of these tiny plants were not digested and lived on in the animal cells, eventually giving rise to chloroplasts.

这些微小植物并无法消化和吸收这些动物细胞，最终形成了叶绿体。

Tripos is in turn eaten by other mixotrophic algae, providing frequent opportunity for exchange of organelles such as chloroplasts.

角藻又被其他混合营养藻类吞食，为叶绿体等细胞器的交换提供频繁的机会。

You won't find chloroplasts in animals — they're more of a plant thing. You wouldn't understand, Blobfish.

你在动物身上找不到叶绿体——它们更像是植物的组成部分。你不会明白的，水滴鱼。

Each leaf parenchyma cell can hold hundreds of chloroplasts — that's where all the photosynthesis happens and what gives leaves their signature green color.

每个薄壁细胞可以容纳数百个叶绿体——这是光合作用发生的地方，也是树叶标志性的绿色的来源。

Meanwhile, the slug adjusts its gene expression to improve its relationship with the chloroplasts and removes damaged plastids to avoid accumulation of potentially damaging chemicals.

与此同时，鼻涕虫通过调整自身的因表达改进与叶绿体的相互作用并去除受损的质体，从而避免具有潜在破坏性化合物的累积。

Chloroplasts need things that the algae provide to themthat animals shouldn't be able to do.

叶绿体需要藻类为它们提供的动物无法提供的东西。

Chloroplasts engage in photosynthesis and are restricted to algae and plants.

叶绿体进行光合作用，仅存在于藻类和植物中。

And if we ever see a lot of chloroplasts that means we're doing photosynthesis.

如果我们看到大量叶绿体，那就意味着我们正在进行光合作用。